- this groups the builds together properly

Stops vertical velocity bias errors preventing the vehicle from landing.
Use of the vertical derivative is blended in so that for zero vertical velocity set point, the  local_position.vz is used and when the magnitude of the vertical velocity setpoint exceeds the landing speed, the  local_position.z_deriv is used.

Using the vertical derivative estimate prevents vertical velocity offsets caused by estimation vertical velocity errors preventing the vehicle disarming.

Previous check level was less than the max achievable by the estimator using current default parameters making the check ineffective.

* Fix description of GPS check fail bits in estimator status message

 - this saves build resources, but makes finding the actual failure rather hard (with the current blue ocean gui).

 - combine default and rtps builds (ccache)
 - set CCACHE_BASEDIR

 - fixes #8436